Apical Transport of Influenza A Virus Ribonucleoprotein Requires Rab11-positive Recycling Endosome

Abstract

Influenza A virus RNA genome exists as eight-segmented ribonucleoprotein complexes containing viral RNA polymerase and nucleoprotein (vRNPs). Packaging of vRNPs and virus budding take place at the apical plasma membrane (APM). However, little is known about the molecular mechanisms of apical transport of newly synthesized vRNP. Transfection of fluorescent-labeled antibody and subsequent live cell imaging revealed that punctate vRNP signals moved along microtubules rapidly but intermittently in both directions, suggestive of vesicle trafficking. Using a series of Rab family protein, we demonstrated that progeny vRNP localized to recycling endosome (RE) in an active/GTP-bound Rab11-dependent manner. The vRNP interacted with Rab11 through viral RNA polymerase. The localization of vRNP to RE and subsequent accumulation to the APM were impaired by overexpression of Rab binding domains (RBD) of Rab11 family interacting proteins (Rab11-FIPs). Similarly, no APM accumulation was observed by overexpression of class II Rab11-FIP mutants lacking RBD. These results suggest that the progeny vRNP makes use of Rab11-dependent RE machinery for APM trafficking.

At the Intersection of the Pathways for Exocytosis and Autophagy

“…Rab11 is important for the anterograde trafficking of; numerous membrane receptors (Chernyshova et al, 2011), the epithelial sodium channel complex of the cortical collecting duct of the kidneys (Butterworth et al, 2012), and DE-Cadherin in polarised cells (Langevin et al, 2005;Wu et al, 2005;Zhang et al, 2004), as well as the calcium dependent exocytosis of growth hormones (Ren et al, 1998;Takaya et al, 2007). A number of intracellular pathogens, such as Porphyromonas gingivalis, influenza A and HIV, have been reported to hi-jack Rab11 dependent anterograde trafficking as a means of escape from host cells (Kadiu & Gendelman, 2011;Momose et al, 2011;Takeuchi et al, 2011). …”

Influenza A virus ribonucleoproteins modulate host recycling by competing with Rab11 effectors

“…Recently, it has been shown that IAV vRNPs attach to Rab11 vesicles after nuclear export, and depletion of the two isoforms of Rab11 (Rab11a and Rab11b, henceforward Rab11 refers to both isoforms) impacts negatively on viral production (Amorim et al, 2011;Avilov et al, 2012b;Eisfeld et al, 2011;Momose et al, 2011). Rab11 is the master regulator of the recycling endosome, described as a web of tubulovesicular membranes (Mobius et al, 2003), that deliver endocytosed proteins and lipids, as well as material segregated from the trans-Golgi network, to the surface.…”

“…Rab11 is the master regulator of the recycling endosome, described as a web of tubulovesicular membranes (Mobius et al, 2003), that deliver endocytosed proteins and lipids, as well as material segregated from the trans-Golgi network, to the surface. Given their function, it has been postulated that the recycling endosome transports vRNPs to the surface using the microtubule network (Amorim et al, 2011;Momose et al, 2011). Later, it was shown that several vRNPs colocalize in a Rab11-dependent manner in cytosolic puncta that increase in size with infection, which led to the proposal that assembly of the 8-segment core occurs en route to the surface (Chou et al, 2013;Lakdawala et al, 2014).…”

“…Two studies have implicated the PB2 subunit of the viral polymerase in binding (Amorim et al, 2011;Momose et al, 2011), although it is unclear whether the interaction is indirect. Second, the morphology and cellular spatial arrangements of Rab11a vesicles carrying vRNPs is undefined at an ultrastructural level and could reveal rearrangements on Rab11 membranes during infection, providing clues as to their role.…”

Influenza A Virus Multiplication and the Cellular SUMOylation System

“…Previous studies demonstrated through the use of live imaging microscopy that, upon entering the cytoplasm, vRNP complexes associate with a pericentriolar recycling endosome marker called Rab11, which is involved in endosomal recycling and trafficking [130]. The accumulation of vRNPs at the microtubule-organizing center after nuclear export, allows them to interact with Rab11-positive recycling endosomes and migrate along microtubules to the sites of budding at the apical surface of the plasma membrane [131][132][133].…”